Heat exchanger and air conditioner using the same

ABSTRACT

Disclosed herein is a heat exchanger for use in an air conditioner. The heat exchanger is provided with a path switching unit at a tube that forms a refrigerant path. The path switching unit is used to switch the flow path of a refrigerant passing through the tube in accordance with a cooling or heating load, thereby regulating the flow rate of the refrigerant. The use of the path switching unit has the effect of achieving an effective control of cooling or heating capacity thereof based on an external load.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air conditioner, and, more particularly, to a heat exchanger which contains a path switching member for switching the flow path of a refrigerant, thereby achieving easy control of cooling or heating capacity based on an external load, and an air conditioner using the same.

2. Description of the Related Art

Generally, an air conditioner is an apparatus for cooling or heating a room, in order to create a more pleasant room environment. The air conditioner sucks indoor air to heat or cool the air, and discharges the heated or cooled air into a room.

FIG. 1 is a configuration diagram schematically illustrating a conventional air conditioner. FIG. 2 is a configuration diagram schematically illustrating the interior of a conventional heat exchanger.

As shown in FIG. 1, the conventional air conditioner comprises: a compressor 2 to compress low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure state; a condenser to condense the refrigerant, discharged from the compressor 2, into liquid refrigerant by emitting heat to the surroundings (i.e. an outdoor heat exchanger 4 upon cooling, or indoor heat exchanger 8 upon heating); an expansion member 6 to expand the liquid refrigerant, condensed by the condenser, into a low-temperature and low-pressure 2-phase gas/liquid refrigerant; and an evaporator to change the 2-phase refrigerant into the gaseous refrigerant by absorbing heat from the surroundings (i.e. the indoor heat exchanger 8 upon cooling, or outdoor heat exchanger 4 upon heating).

The compressor 2 is a constant-speed compressor having a constant capacity. In this type of compressor, a bypass member 10 is installed between suction and discharge portions of the compressor 2, in order to control the capacity of the compressor 2 when a desired cooling load is low as compared to the capacity of the compressor 2.

The bypass member 10 includes: a bypass path 12 to connect the suction and discharge portions of the compressor 2; and an opening/closing valve 14 provided at the bypass path 12 to open or close the bypass path 12.

The indoor heat exchanger 4 includes: a panel shaped heat exchanger body 16 to perform a heat exchange operation between a refrigerant and outdoor air; a suction header 18 provided at a side of the heat exchanger body 16 to suck the refrigerant discharged from the compressor 2; one or more tubes 20 branched from the suction header 18; and a discharge header 22 to discharge the heat exchanged refrigerant, the tubes 20 being merged at the discharge header 22.

The interior configuration of the indoor heat exchanger is applicable to the outdoor heat exchanger in the same manner.

When the conventional air conditioner having the above-described configuration performs a cooling operation, first, the high-temperature and high-pressure refrigerant, discharged from the compressor 2, is introduced into the outdoor heat exchanger 4 that serves as a condenser. Thereby, the refrigerant emits heat to the surroundings.

Subsequently, the refrigerant, having passed through the outdoor heat exchanger 4, expands into a low-temperature and low-pressure state while passing through the expansion member 6. After that, the low-temperature and low-pressure refrigerant is introduced into the indoor heat exchanger 8.

Once being introduced into the indoor heat exchanger 8, the refrigerant absorbs heat from indoor air, thereby achieving the cooling of a room.

Meanwhile, when it is necessary to reduce the capacity of the compressor 2, the opening/closing valve 14 is opened, so that a part of the refrigerant, discharged from the compressor 2, is again introduced into the suction portion of the compressor 2 via the bypass path 12.

Disadvantages of the conventional air conditioner includes the fact that, as a method for controlling the cooling capacity of the air conditioner based on a cooling load, it attempts to bypass the refrigerant discharged from the compressor 2 to regulate the flow rate of the refrigerant. However, there is a limitation to vary the flow rate of the refrigerant being bypassed, based on an external load. Further, seeing that the consumption of electricity, required to drive the compressor 2, is constant, the conventional air conditioner exhibits excessive electricity consumption, suffering from low energy efficiency.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a heat exchanger in which a refrigerant path switching unit is provided, thereby achieving an appropriate control of cooling or heating capacity based on a varying external load, and an air conditioner using the same.

In accordance with the present invention, the above and other objects can be accomplished by the provision of a heat exchanger comprising: a refrigerant path defined inside a heat exchanger body for the passage of a refrigerant; and at least one path switching unit provided at the refrigerant path to switch the flow path of the refrigerant, in order to regulate the flow rate of the refrigerant passing through the refrigerant path.

Preferably, the path switching unit may include: a bypass path to bypass the refrigerant passing through the refrigerant path; and an opening/closing valve to open or close the bypass path.

Preferably, the at least one path switching unit may include a plurality of path switching units.

Preferably, the refrigerant path may include: a suction header to suck the refrigerant; a discharge header to discharge the heat exchanged refrigerant; and at least one tube to connect the suction header to the discharge header for the passage of the refrigerant.

Preferably, the bypass path may be formed between the tube and the discharge header.

Preferably, the opening/closing valve may be installed at a connection location between the refrigerant path and the bypass path.

Preferably, the opening/closing valve may be a 3-way valve.

Preferably, the at least one tube may include a plurality of tubes branched from the suction header.

Preferably, the at least one path switching unit may include a plurality of path switching units, and the bypass path of each of the path switching units is connected to an associated one of the tubes.

Preferably, the tube may have a multiple-bend shape, and the bypass path may connect a bent portion of the tube to the discharge header.

In the heat exchanger for use in an air conditioner according to the present invention, as a result of installing the path switching units at the tubes that form refrigerant paths, it is possible to regulate the flow rate of the refrigerant by switching the flow path of a refrigerant passing through the tubes in accordance with a cooling or heating load. This has the effect of achieving an effective control of cooling or heating capacity thereof based on an external load.

Further, when the heat exchanger provided with the path switching unit is used along with a variable capacity compressor, a variation of capacity is possible even under a low load condition with reduced electricity consumption.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a configuration diagram schematically illustrating a conventional air conditioner;

FIG. 2 is a configuration diagram schematically illustrating the interior of a conventional heat exchanger;

FIG. 3 is a configuration diagram schematically illustrating an air conditioner according to an embodiment of the present invention; and

FIG. 4 is a configuration diagram schematically illustrating the interior of a heat exchanger according to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a configuration diagram schematically illustrating an air conditioner according to an embodiment of the present invention. FIG. 4 is a configuration diagram schematically illustrating the interior of a heat exchanger provided in the air conditioner according to the embodiment of the present invention.

As shown in FIG. 3, the air conditioner according to the present invention comprises: a compressor 50 to compress low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure state; a condenser to condense the refrigerant, discharged from the compressor 50, into liquid refrigerant by emitting heat to the surroundings (i.e. an outdoor heat exchanger 52 upon cooling, or indoor heat exchanger 54 upon heating); an expansion member 56 to expand the liquid refrigerant, condensed by the condenser, into a low-temperature and low-pressure 2-phase gas/liquid refrigerant; and an evaporator to change the 2-phase refrigerant into gaseous refrigerant by absorbing heat of the surroundings (i.e. the indoor heat exchanger 54 upon cooling, or outdoor heat exchanger 52 upon heating).

The compressor 50 may be a constant-speed compressor having a constant capacity, or may be a variable capacity compressor. The following description is limited to the use of the constant-speed compressor.

The indoor heat exchanger 54 includes: a refrigerant path defined inside a heat exchanger body 64 for the passage of the refrigerant; and a path switching unit 70 to switch the flow path of the refrigerant, in order to regulate the flow rate of the refrigerant passing through the refrigerant path.

The refrigerant path includes: a suction header 60 to suck the refrigerant; a discharge header 62 to discharge the heat exchanged refrigerant; and a plurality of tubes to connect the suction header 60 to the discharge header 62 for allowing for the passage of the refrigerant from the suction header 60 to the discharge header 62.

The plurality of tubes are branched from the suction header 60, and each has a multiple-bend shape.

The discharge header 62 is configured so that the plurality of tubes are merged thereat.

The heat exchanger body 64 has a panel shape. The plurality of tubes are enclosed by the heat exchanger body 64. Both the suction header 60 and the discharge header 62 may be arranged at a side of the heat exchanger body 64 together, or may be arranged at both sides of the heat exchanger body 64, respectively.

In association with the plurality of tubes, the following description is limited to only two tubes, i.e. a first tube 66 and a second tube 68.

One end of each of the first and second tubes 66 and 68 is connected to the suction header 60, and the other ends of the first and second tubes 66 and 68 are connected to the discharge header 62.

The path switching unit 70 includes: first and second bypass paths 72 and 76; and opening/closing valves 74 and 78 to open or close the first and second bypass paths 72 and 76, respectively. The first and second bypass paths 72 and 76 connect bent portions of the first and second tubes 66 and 68 to the discharge header 62, respectively, to bypass the refrigerant, passing through the first and second tubes 66 and 68, to the discharge header 62.

Although the embodiment of the present invention is limited to the design wherein both the first and second bypass paths 72 and 76 are provided at selected bent portions of the first and second tubes 66 and 68, respectively, it should be understood that the present invention is not limited to the embodiment, and a plurality of bypass paths may be provided at a plurality of locations of the first and second tubes 66 and 68.

The opening/closing valves 74 and 78 are 3-way valves installed between the selected bent portions of the first and second tubes 66 and 68 and the first and second bypass paths 72 and 76. In accordance with the operation of the opening/closing valves 74 and 78, the first and second bypass paths 72 and 76 are opened when it is necessary to reduce the flow rate of the refrigerant in accordance with a low cooling load, whereas are closed when the flow rate of the refrigerant is appropriate for a desired cooling load.

In an alternative embodiment of the present invention, solenoid valves may be installed at the first and second bypass paths 72 and 76, respectively, to open or close the bypass paths 72 and 76.

Hereinafter, the operation of the air conditioner having the indoor heat exchanger according to the present invention as stated above will be explained.

When the air conditioner of the present invention operates in cooling mode, first, the high-temperature and high-pressure refrigerant, compressed in the compressor 50, is introduced into the outdoor heat exchanger 52 that serves as a condenser. Thereby, the refrigerant emits heat to the surroundings.

Subsequently, the refrigerant, having passed through the outdoor heat exchanger 52, expands into a low-temperature and low-pressure state while passing through the expansion member 56. After that, the low-temperature and low-pressure refrigerant is introduced into the indoor heat exchanger 54.

Once being introduced into the indoor heat exchanger 54, the refrigerant is divided by way of the suction header 60, to be introduced into the first and second tubes 66 and 68. Thereby, the refrigerant is heat exchanged with indoor air while passing through the first and second tubes 66 and 68. Then, after being discharged from the discharge header 62, the refrigerant is again circulated into the compressor 50.

As stated above, the refrigerant absorbs heat from indoor air while passing through the indoor heat exchanger 54, thereby cooling a room.

In this case, when a cooling load is low, the first and second 3-way valves 74 and 78 operate to open the first and second bypass paths 72 and 76.

If the first and second bypass paths 72 and 76 are opened, the refrigerant, passing through the first and second tubes 66 and 68 of the indoor heat exchanger 54, is bypassed into the first and second bypass paths 72 and 76 through the first and second 3-way valves 74 and 78.

When a cooling load is low, bypassing the refrigerant, passing through the first and second tubes 66 and 68, into the first and second bypass paths 72 and 76, effectively reduces a heat exchange between the refrigerant and the indoor air, so that the refrigerant takes less heat from the indoor air. This ensures the cooling degree of a room can be lowered in proportional to the low cooling load.

Accordingly, the cooling temperature of a room can be regulated with a high cooling load sensitivity.

Meanwhile, although the above description is limited to install the path switching unit 70 in the indoor heat exchanger 54, the path switching unit 70 may be provided at the outdoor heat exchanger 52 to switch the flow path of the refrigerant passing through the outdoor heat exchanger 52 based on a heating load, for enabling a control of heating capacity.

Also, in an alternative embodiment of the present invention, the compressor 50 may be a variable capacity compressor. Using the variable capacity compressor has several advantages. For example, the size of the refrigerant path inside the heat exchanger as well as the consumption of electricity required to drive the compressor can be reduced. Also, more sensitive response to a cooling load is possible, and therefore, an enhancement in cooling efficiency can be achieved.

As apparent from the above description, a heat exchanger for use in an air conditioner according to the present invention has the following advantageous effects.

Firstly, according to the present invention, a path switching unit is provided in the heat exchanger at a tube that forms a refrigerant path. The path switching unit is used to switch the flow path of a refrigerant passing through the tube in accordance with a cooling or heating load, thereby regulating the flow rate of the refrigerant. The use of the path switching unit has the effect of achieving an effective control of cooling or heating capacity thereof based on an external load.

Secondly, when the heat exchanger provided with the path switching unit is used along with a variable capacity compressor, a variation of capacity is possible even under a low load condition with reduced electricity consumption.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. A heat exchanger comprising: a refrigerant path defined inside a heat exchanger body for the passage of a refrigerant; and at least one path switching unit provided at the refrigerant path to switch the flow path of the refrigerant, in order to regulate the flow rate of the refrigerant passing through the refrigerant path.
 2. The heat exchanger as set forth in claim 1, wherein the path switching unit includes: a bypass path to bypass the refrigerant passing through the refrigerant path; and an opening/closing valve to open or close the bypass path.
 3. The heat exchanger as set forth in claim 2, wherein the at least one path switching unit includes a plurality of path switching units.
 4. The heat exchanger as set forth in claim 2, wherein the refrigerant path includes: a suction header to suck the refrigerant; a discharge header to discharge the heat exchanged refrigerant; and at least one tube to connect the suction header to the discharge header for the passage of the refrigerant.
 5. The heat exchanger as set forth in claim 4, wherein the bypass path is formed between the tube and the discharge header.
 6. The heat exchanger as set forth in claim 2, wherein the opening/closing valve is installed at a connection location between the refrigerant path and the bypass path.
 7. The heat exchanger as set forth in claim 2, wherein the opening/closing valve is a 3-way valve.
 8. The heat exchanger as set forth in claim 4, wherein the at least one tube includes a plurality of tubes branched from the suction header.
 9. The heat exchanger as set forth in claim 8, wherein the at least one path switching unit includes a plurality of path switching units, and the bypass path of each of the path switching units is connected to an associated one of the tubes.
 10. The heat exchanger as set forth in claim 4, wherein the tube has a multiple-bend shape, and wherein the bypass path connects a bent portion of the tube to the discharge header.
 11. An air conditioner using a heat exchanger, comprising: a compressor to compress a refrigerant into a high-temperature and high-pressure state; an indoor heat exchanger to perform a heat exchange between the refrigerant, discharged from the compressor, and indoor air; an expansion member to expand the refrigerant discharged from the indoor heat exchanger; and an outdoor heat exchanger to perform a heat exchange between the refrigerant discharged from the expansion member and outside air, wherein each of the indoor heat exchanger and the outdoor heat exchanger comprises: a refrigerant path defined inside a heat exchanger body for the passage of the refrigerant; and at least one path switching unit provided at the refrigerant path to switch the flow path of the refrigerant, in order to regulate the flow rate of the refrigerant passing through the refrigerant path.
 12. The air conditioner as set forth in claim 11, wherein the path switching unit includes: a bypass path to bypass the refrigerant passing through the refrigerant path; and an opening/closing valve to open or close the bypass path.
 13. The air conditioner as set forth in claim 12, wherein the at least one path switching unit includes a plurality of path switching units.
 14. The air conditioner as set forth in claim 12, wherein the refrigerant path includes: a suction header to suck the refrigerant; a discharge header to discharge the heat exchanged refrigerant; and at least one tube to connect the suction header to the discharge header for the passage of the refrigerant.
 15. The air conditioner as set forth in claim 14, wherein the bypass path is formed between the tube and the discharge header.
 16. The air conditioner as set forth in claim 12, wherein the opening/closing valve is installed at a connection location between the refrigerant path and the bypass path.
 17. The air conditioner as set forth in claim 12, wherein the opening/closing valve is a 3-way valve.
 18. The air conditioner as set forth in claim 14, wherein the at least one tube includes a plurality of tubes branched from the suction header.
 19. The air conditioner as set forth in claim 18, wherein the at least one path switching unit includes a plurality of path switching units, and the bypass path of each of the path switching units is connected to an associated one of the tubes.
 20. The air conditioner as set forth in claim 14, wherein the tube has a multiple-bend shape, and wherein the bypass path connects a bent portion of the tube to the discharge header. 